1. Field of the Invention
The present invention is related to a method and an apparatus for inspecting the contours of a gear, particularly to a method and an apparatus for fast, accurately and efficiently measuring the manufacturing errors of the contours of a precision involute spur gear.
2. Description of the Prior Art
Conventionally, the measurements of the manufacturing errors of a spur gear are accomplished by using a probe and a dial gage. In view that this process requires a direct mechanical contact with the gear teeth, the measurement of one single gear takes much a long time and requires a highly skilled operator. When measuring a precision miniature spur gear, a profile projector is used first to magnify and project the gear image on a screen. The measurements are then taken by manually comparing the projected gear image with a standard gear pattern. This process is also quite time-consuming.
In view of the plenty of time spent on the inspection of one single gear by the two measuring methods, only a few samples are selected for inspection in the quality control process among a large number of mass manufactured gears. Moreover, the accuracy of the measurements is dependent highly on the skills of the operator. In this manner, the results of the measurement may be notably diversified among different operators. Thus, the quality of a large number of mass produced gears is certainly not very well assured.